The telecommunications industry utilizes a variety of electrical connectors in several different situations in which electrical connections must be made. One such situation is the providing of electrical connections between a telephone cable and a service cable at an individual customer site, mainly through use of a splice of the tip and ring signal wires of a drop wire from the main cable to respective house wires of the service cable at a junction located outside or inside the house. Ends of both the drop wire and the service cable enter an enclosure, and the tip and ring wires of each are interconnected or spliced to the tip and ring wires of the other in a terminal block, commonly termed a crossconnect block. Such a crossconnect block must not only provide dielectric protective structure around the splice, but together with the enclosure must provide protection from the environment, especially from water, dust, and other contaminants and also from insects and animals. Such enclosures must be capable of being reopened to expose the crossconnect blocks and other electrical connectors therein for service and repair as needed. Also, certain terminal blocks are utilized to provide protection of the individual circuits from voltage and current surges for safety reasons and for the protection of sensitive electrical and electronic equipment from damage.
One such crossconnect block is disclosed in U.S. Pat. No. 5,219,302. A dielectric housing includes a pair of tubular terminal-receiving housing sections each with an integrally molded center post therewithin extending upwardly from a common base section, thus defining an annular cavity within which is disposed a barrel-shaped terminal and a tubular actuator adapted to rotate the terminal from an unterminated position to a terminated position. Each housing section is provided with a pair of wire-receiving openings through side walls and into the cavity aligned with an aperture through the center post, and associated openings are provided in contact sections of the terminal and in the actuator that are aligned with the side wall openings when the terminal and actuator are ill the unactuated position. Slot walls of the terminal extend circumferentially from each wire-receiving opening and are precisely profiled to include constricted edges to penetrate the wire insulation and assuredly engage the conductor therewithin. During splicing, the wire ends of both tip wires (or both ring wires) are inserted into respective openings of the same housing section and through the apertured contact sections of the terminal and into the center post until stopped by abutment against a stop surface. Upon rotation of the rotatable terminal by the actuator such as through a quarter turn, slot walls of the terminal pierce the insulation of the respective wires and engage the respective conductors thereof, thus commoning and interconnecting them.
U.S. Pat. Nos. 5,317,474 and 5,321,577 both disclose a similar terminal block in which is contained one or two surge-protecting electrical components or protectors. The circuits of the wires terminated within the terminal block are provided-with protection against voltage and current surges by the protectors. Both terminal blocks utilize similar housing structure and terminals and actuators for the insulation displacement termination of unstripped wires as in U.S. Pat. No. 5,219,302.
In U.S. Pat. No. 5,219,302 and also in U.S. Pat. No. 5,006,077, such terminal blocks with rotatable terminals in annular housing cavities are adapted to accommodate wires of two particular sizes. While wire entrance apertures of the housing section sidewalls are wide enough to receive a larger 18 AWG size wire therethrough, the wire-receiving passageways of the center post are profiled to receive and stop the end of the 18 AWG wire at a tapered transition section located between the larger diameter forward passageway portion and a smaller diameter passageway portion. The tapered transition portion acts as a lead-in to prevent stubbing, to permit the end of a smaller 24 AWG wire to pass completely through and exit from the center post and continue therebeyond (and through apertures in the terminal and actuator) until stopped by a stop recess in the far annular cavity sidewall opposed from the wire entrance apertures. When the smaller diameter wire is thus extended completely through and beyond the center post, the far portion of the terminal through which the free end of the wire extends is provided with a smaller diameter slot to assuredly engage the smaller diameter conductor within the 24 AWG wire; the larger diameter slot adjacent the wire entrance is useful in biting into the insulation and establishing a strain relief protecting the termination from forces otherwise transmittable to the end of wire.
Quiet Front crossconnect and protected terminal blocks are sold commercially by AMP Incorporated and contain sealant material that embeds the terminal in each housing cavity (and the protector component, if any) and also embeds the end of each wire inserted into and terminated by the terminal block. Such sealant material is preferably gel-like and may be as disclosed in U.S. patent application Ser. No. 07/955,535 filed Oct. 1, 1992 and also may be one of several materials disclosed in European Pat. Publication No. 0 529 957 A1. It is common that regarding very small gage wires, once a wire end has been inserted into the housing section and then released to manually rotate the actuator for actuation of the terminal for termination to the wire end, such material, especially material of gel-like consistency tends to urge the inserted wire end at least partially out of the housing. Thus it is possible that the free end of the wire may be moved sufficiently toward the wire entrance that it no longer resides in the wire end recess of the cavity sidewall and may not become terminated upon rotation of the terminal.
It is desired to provide a terminal block filled with sealant material such as gel-like material, that permits an indication that the wire end is fully inserted.
It is desired to provide a terminal block filled with sealant material such as gel-like material, that assures that the wire end remains fully within the terminal block after insertion but prior to termination.